| 摘要 |
PURPOSE:To prevent gas from eaking by a method wherein a groove, which is hollowed toward the direction opposite to a cavidy side so as to surround a gas pouring part, is provided at the tip surface of a gas pouring member facing a cavity so as to communicate the groove with the cavity. CONSTITUTION:The pouring of gas is started under the condition that the surface layer of filled molten resin is under semi-solidified state. High pressure gas waiting in a gas flow path 20 flows through a through hole 18 and a gas pouring part 19 into molten resin. Though tending to escape through a gap between the front surface of a casing 12 and a fixed mold main body 3, the inflowing gas can not escape outside by being blocked with the molten resin filled in a groove 23 surrounding the gas pouring part. The high pressure gas effectively goes into the resin without being lost. The entering gas presses the un-solidified interior resin against the side face of a cavity and proceeds in thicker walled part, resulting in forming a hollow part within the resin. When a molded article is solidified after the hollow part is formed under the above-mentioned state, the molded article is released from the mold. In this case, the releasing can be smoothly carried out due to the form, which is divergent to the cavity 6 side, of the groove 23. |
